The Nord Stream pipelines, which transported natural gas from Russia to Europe, were destroyed by a pro-Ukrainian group, according to new intelligence reviewed by U.S. officials, according to the New York Times on Tuesday. However, there was no proof of Kyiv government involvement in the September 2022 attack.

U.S. officials could not be immediately reached for comment, and Reuters was unable to independently verify the allegation. It was unable to reach officials from the governments of Russia or Ukraine right away.

“The city is an important hub for defending Ukrainian troops in the Donbas. Taking it under control will allow further offensive actions to be conducted deep into Ukraine’s defensive lines.”

Western strategists say the ruined city has limited value, and Russia’s assault may aim for a symbolic victory after a winter offensive involving hundreds of thousands of conscripted reservists and fighters from the Wagner private army.

Ukraine’s military command reported a record 1,600 Russians killed over the previous 24 hours. Moscow said Ukraine’s losses in February had risen 40% from January to 11,000.

Tolls of enemy dead cannot be confirmed and the sides do not release regular data on their own casualties, but past Ukrainian reports of spikes in Russian losses have corresponded with failed Russian assaults.

Reuters journalists have not been inside Bakhmut for a week and could not independently verify the situation there.

Urban warfare typically favours defenders. Some Ukrainian officials have spoken in recent days of a ratio of as many as seven Russians killed at Bakhmut for every Ukrainian lost.